Potential pathogens and effective disinfectants on public telephones at a large urban United States university

Telephones can carry potential bacterial pathogens, posing a risk for transfer of pathogens to users' hands. This study examined 25 mouthpieces of public telephones at a large urban U.S. university located in an area of rising incidence of community-acquired staphylococcal infections. Coagaulase-negative staphylococci were most commonly isolated (64% of mouthpieces). Potential pathogens isolated included Staphylococcus aureus, vancomycin-susceptible Enterococcus, and Klebsiella ozaenae. The efficacy of disinfectants on reducing bacterial counts on telephone mouthpieces was also investigated. Staphyloccocus aurens, Pseudomonas aeruginosa, and Enterococcusfaecalis were inoculated onto mouthpieces and challenged with disinfectant wipes. Bacterial counts were reduced substantially for all three organisms by wipes containing either 70% isopropyl alcohol, 1.84% sodium hypochlorite, or quaternary ammonium compounds. The sodium hypochlorite-based cleaner demonstrated 100% efficacy at removing or killing test organisms from telephone mouthpieces. These data suggest that tested cleaners may be appropriate and needed for public telephone disinfection.